Abstract

Contributed Talk - Splinter GalaxyClusters

Tuesday, 08 September 2026, 16:05   (MW-1050)

A dense cosmic knot around an extremely red quasar at z ~3 discovered with the JWST

Dominika Wylezalek
Heidelberg University

Red quasars, heavily dust-obscured active galactic nuclei, are thought to represent a key evolutionary phase in which powerful feedback begins to expel gas and dust from the host galaxy. Whether this phase is linked to preferential environments remains an open question. In this talk, I will present JWST observations of the field around the luminous red quasar J1652 at z ~ 3, revealing a spectacular protocluster with a galaxy overdensity exceeding a factor of 15. The system shows clear substructure in position-velocity space consistent with a merger of two dark matter haloes, and is already transitioning from a site of active star formation to one hosting massive quiescent galaxies. I will discuss what this system may tell us about the co-evolution of extreme AGN and their large-scale environments at cosmic noon.